1. Field of the Invention
The present invention relates to an information processing apparatus for generating ranking information representing the degree of popularity of content data such as photographs as well as the degree of popularity of metadata, and also to an information processing method therefor.
2. Description of the Related Art
There is a technique called variable data print (VDP), which makes use of features of a digital image forming apparatus. This technique enables changing the content to be printed each time according to information in a database.
Print data in a VDP system is referred to as VDP data. An application which generates the VDP data is referred to as a VDP application. The VDP application provides the user with a user interface which performs page layout processing. The VDP application determines a region for arranging an object, i.e., position, size, and type (text, image, graphics, etc.) of the region since the object may change according to a database. A region whose content changes with a database record is referred to as a variable region, and a region whose content does not change with a database record is referred to as a fixed region.
For example, the user sets up an image layout rule using each column of the database so that the content of a variable region changes with a database record. For example, the user can set up the following image layout rule: when the value of “Age” in a database record is 20-29, the user arranges a photographic image for young people to the relevant region; when it is 60 or older, the user arranges a photographic image for elderly people to the relevant region.
In this way, the VDP application generates VDP data which associates each region on a page with the database and then transmits the VDP data to a digital image forming apparatus. Then, when the digital image forming apparatus receives the VDP data, it prints images according to the associations in the VDP data.
After the VDP application generates the VDP data associating each region on a page with the database, the user may want to change an image inserted into the VDP data to another photograph. Since the VDP application automatically determines images to be arranged in each region as mentioned above, images are not necessarily reflected to the VDP data as the user intends.
When the user revises a certain image on the VDP data to another one, it is very troublesome for the user to find a desired photograph by browsing all candidate photographs. One possible method for saving the effort of finding a desired photograph is to add metadata to photographs in advance and use the metadata as a search keyword to narrow down candidate photographs. In this case, a plurality of users may revise images inserted into their respective VDP data. For example, a plurality of users who received a personalized photo album revise images therein. In this case, each user will find it useful to know metadata added to a popular photograph among many other users in selecting metadata as a search keyword to narrow down candidate photographs.
Some of conventional content retrieval systems numerically represent the degree of popularity of the content itself as well as the degree of popularity of search keyword and metadata by using diverse methods.
Japanese Patent Application Laid-Open No. 2005-332087 discusses a technique for calculating which program is recommended to a user based on user's operation history information enabling effectively recommending a program to the user from the early stage of service operation. Japanese Patent Application Laid-Open No. 2006-260337 discusses a technique for giving, when a user retrieves or displays a certain content on the Internet, a score representing the degree of popularity to the content.
Japanese Patent Application Laid-Open No. 2004-096479 discusses a technique for calculating the degree of popularity of metadata and then visually presenting the degree of popularity to the user by using a tag cloud. The tag cloud is a function to display a list of metadata names in different font sizes based on the degree of popularity from all users for each piece of metadata.
Conventional techniques calculate the degree of popularity for each content based only on the number of times of using metadata as a search keyword and the number of times of selection of content by the user. However, some photographs may be retained in the VDP data since the start of the editing period (initial stage) without being replaced because they are user's favorites.
Therefore, conventional techniques cannot evaluate the degree of popularity of metadata added to a photograph or the degree of popularity of the photograph itself. Accordingly, conventional techniques have a situation that user preferences are not appropriately reflected to the degree of popularity of metadata of a photograph or the degree of popularity of the photograph itself among users.